Add block_comment to JS, TSX, and TS (#31400)

This is the first step of ["Solution proposal for folding multiline
comments with no
indentation"](https://github.com/zed-industries/zed/discussions/31395):

> 1. Add block_comment in the config.toml for the languages javascript,
typescript, tsx. These are simple languages for this feature, and I am
already familiar with them.

The next step will be:

> 2. Modify the function `crease_for_buffer_row` in `DisplaySnapshot` to
handle multiline comments. `editor::fold` and `editor::fold_all` will
handle multiline comments after this change. To my knowledge,
`editor::unfold`, `editor::unfold_all`, and the **unfold** indicator in
the gutter will already work after folding, but there will be no
**fold** indicator.

Release Notes:

- N/A

crates/languages/src/javascript/config.toml

@@ -4,6 +4,7 @@ path_suffixes = ["js", "jsx", "mjs", "cjs"]
 # [/ ] is so we match "env node" or "/node" but not "ts-node"
 first_line_pattern = '^#!.*\b(?:[/ ]node|deno run.*--ext[= ]js)\b'
 line_comments = ["// "]
+block_comment = ["/*", "*/"]
 autoclose_before = ";:.,=}])>"
 brackets = [
     { start = "{", end = "}", close = true, newline = true },

crates/languages/src/tsx/config.toml

@@ -2,6 +2,7 @@ name = "TSX"
 grammar = "tsx"
 path_suffixes = ["tsx"]
 line_comments = ["// "]
+block_comment = ["/*", "*/"]
 autoclose_before = ";:.,=}])>"
 brackets = [
     { start = "{", end = "}", close = true, newline = true },

crates/languages/src/typescript/config.toml

@@ -3,6 +3,7 @@ grammar = "typescript"
 path_suffixes = ["ts", "cts", "d.cts", "d.mts", "mts"]
 first_line_pattern = '^#!.*\b(?:deno run|ts-node|bun|tsx)\b'
 line_comments = ["// "]
+block_comment = ["/*", "*/"]
 autoclose_before = ";:.,=}])>"
 brackets = [
     { start = "{", end = "}", close = true, newline = true },